• Title/Summary/Keyword: SC Wall

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THE EFFECTS OF WALL BOUNDARY CONDITIONS ON MASS TRANSFER IN TURBULENT PIPE FLOW (난류 파이프 유동 내 물질전달에서의 경계조건 영향)

  • Kang, Chang-Woo;Yang, Kyung-Soo
    • Journal of computational fluids engineering
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    • v.17 no.2
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    • pp.42-52
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    • 2012
  • Direct Numerical Simulation(DNS) of turbulent mass transfer in fully developed turbulent pipe flow has been performed to study the effect of wall boundary conditions on the concentration fields at $Re_{\tau}$=180 based on friction velocity and pipe radius. Fully developed turbulent pipe flows for Sc=0.71 are studied with two different wall boundary conditions, namely, constant mass flux and constant wall concentration. The mean concentration profiles and turbulent mass fluxes obtained from the present DNS are in good agreement with the previous numerical results currently available. To investigate the effects of wall boundary condition on the turbulent mass transfer, the mean concentration profile, root-mean-square of concentration fluctuation, turbulent mass fluxes and higher-order statistics(Skewness and Flatness factor) are compared for the two cases. Furthermore, the budgets of turbulent mass fluxes and concentration variance were computed and analyzed to elucidate the effects of wall boundary conditions on the turbulent mass transfer.

Seismic Performance Evaluation of Unreinforced Masonry Walls with Additional Boundary RC Frames (RC 경계골조를 설치한 신축 비보강 조적벽체의 내진성능 평가)

  • You, Young-Chan;Kim, Min-Sun;Lee, Hyun-Jee
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.11
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    • pp.27-35
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    • 2018
  • The purpose of this study is to examine the effects of boundary RC frame(composed of one tie-beam and two tie-columns) on seismic performance of unreinforced masonry walls to suggest alternative way for seismic design of unreinforced masonry wall structures. Two test specimens are prepared, one is a typical unreinforced masonry wall and another is alternative unreinforced masonry wall with additional boundary RC frame. The structural experiments were carried out to evaluate the difference of seismic resistance performance between two test specimens with or without the boundary RC frames. From the test results, it was found that the failure mode of unreinforced masonry wall fundamentally changed from 'brittle' to 'ductile' by the installing of boundary RC frames. And, the maximum load and energy dissipation capacity of the test specimen with boundary RC frame was increased about 1.6~1.7 and 2~3 times respectively compared with a typical unreinforced masonry wall specimen.

Shear Resistance Capacity Length of Traditional Wooden Frame's Wall divided into Small Frame (세부목골조로 구성된 전통목골조 벽체 전단저항능력)

  • Hwang, Jong-Kook;Kwon, Yang-Hee;Bae, Dong-Hun
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.3
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    • pp.11-18
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    • 2019
  • The purpose of this study was to estimate the resistance capacity of a traditional wooden house with shear walls made of wood panel. In order to achieve the purpose of the study, the load - displacement test was carried out and the resistance moment values of the shear walls were proposed. The shear walls were made by placing studs with a nominal dimension of $38mm{\times}89mm$ at intervals of 600 mm, and attaching 12 mm thick plywood with 8-d size pegs at intervals of 150 mm. The type of traditional building wall was classified and showed the moment resistance ability of each wall type. This value is expressed as a proportional value divided by the moment resisting capacity of the standard size shear walls not divided into the divided small frames. Although some frames have proportional values larger than 1.0 even though they have openings, most of them show values smaller than 1.0. Also, even without the openings, it showed a smaller value than 1, such as 0.84 and 0.67.

Thyroid Function after Postoperative Radiation Therapy in Patients with Breast Cancer

  • Wolny-Rokicka, Edyta;Tukiendorf, Andrzej;Wydmanski, Jerzy;Roszkowska, Danuta;Staniul, Boguslaw;Zembron-Lacny, Agnieszka
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.10
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    • pp.4577-4581
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    • 2016
  • Objective: The aim of this study was to assess thyroid function in breast cancer patients exposed to therapeutic external beam radiation. The focus was on possible progressive changes and any relationships between the incidence of primary hypothyroidism, the time required to become hypothyroid, and factors such as chemotherapy, hormonotherapy and immunotherapy. Materials and Methods: Seventy females undergoing 3D conformal and IMRT radiation therapy for breast cancers were enrolled in a non-randomized prospective study. The patients was divided into two groups: those after mastectomy or breast conserving surgery (BCS) were irradiated to a scar of the chest wall/breast and the ipsilateral supraclavicular and the axillary areas (supraclavicular radiotherapy group - SC-RT group - 32 patients) and the control group receiving adjuvant chest wall/breast RT only (BCT group - 38 patients).The total doses were 50.0 to 70 Gy in 5 to 7 weeks. The median follow-up term was 24 months (range, 1-40 months). Thyroid function was evaluated by measuring thyroid stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3) levels. The minimum, maximum and mean thyroid gland doses for 20 Gy (V20) were calculated for all patients. Results: Statistically significant results were obtained for the SC-RT group. Two yearsa fter the end of RT the chance of an event was increased in 6% of the population (p=0.009) in the SC-RT group. In the BCT group no significance was noted. No statistically significant differences were found for V20, chemio-, immunotherapy and hormonotherapy or Ki67 values (p=0.12). No significant results were obtained for development of hypothyroidism and clinical factors (age, thyroid volume, treatment modalities). Conclusion: Radiotherapy is associated with a higher incidence of thyroid toxicity in breast cancer patients. Routine thyroid function monitoring should be recommended in such cases.

Quality Characterization of Salmon Oil Microencapsulated with Various Wall Materials (다양한 피복물질을 이용한 연어 오일의 미세캡슐화 및 품질 특성)

  • LIM, Hyun-Jung;PARK, Seul-Ki;KIM, Min-Jeong;LEE, Won-Kyung;MIN, Jin-Ki;CHO, Young-Je
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.5
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    • pp.1334-1342
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    • 2015
  • The aim of this study was to investigate the quality characterization of salmon oil microencapsulated with maltodextrin (MD), cyclodextrin (CD), sodium caseinate (SC), arabic gum (AG) and WPI. After spray drying to ambient temperature, the salmon oil powders were packed (single package) and placed at room temperature ($25^{\circ}C$) for 30 day. The quality characterization of salmon oil powder including total oil (%), extractable oil (%), encapsulation efficiency (%), fatty acid, SEM, pH, acid value (AV), peroxide value(POV) were investigated. Salmon oil was microencapsulated with a high power yield (> 80%); including the formulation MD/SC and MD/SC/WPI. The microencapsules of MD/SC/WPI presented spherical shapes, smooth texture and non-porous surfaces. The pH of MD/SC/WPI varied from 6.11 to 5.99 (p>0.05). The AV of MD/SC/WPI varied from 4.74 to 4.61 (p>0.05). The pH and AV were not significantly different. The POV of MD/SC/WPI increased with storage day (p<0.05). It was concluded that MD/SC/WPI could delay lipid oxidation and high yield (82.55%) of salmon oil powder.

Effect of Live Yeast and Mannan-oligosaccharides on Performance of Early-lactation Holstein Dairy Cows

  • Bagheri, M.;Ghorbani, G.R.;Rahmani, H.R.;Khorvash, M.;Nili, N.;Sudekum, K.-H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.6
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    • pp.812-818
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    • 2009
  • This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

An Analysis of Flexural Performance of Concrete Filled Soldier Pile Applied to Temporary Retaining Wall (흙막이 벽체에 적용하는 콘크리트 충전형 엄지말뚝의 휨성능 분석)

  • Park, Yong-Hyeon;Kim, Do-Bumn;Ju, Young-Kyu;Yang, Il-Seung;Yom, Kyong-Soo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.3
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    • pp.19-25
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    • 2019
  • The purpose of this study was to evaluate bending performance of concrete filled soldier pile for temporary retaining wall. Structural performance tests were conducted on total number of four specimens. Each specimen had a unique characteristics with combination of the following variables, existence of reinforcing bar and locations of reinforcing steel plates. The results of this study were as follows; concrete filled steel tubes with being reinforced bar and flange rather than non-bar showed better performance. Higher yield, tensile strength and sufficient plastic strain were archived and maximum moment observed in experiments exceeded theoretical maximum moment in both allowable stress design and limit state design at all specimens.

Structural Behavior on Horizontal Connection for Hybrid Precast Concrete Panel (복합 프리캐스트 콘크리트 패널 수평접합부의 구조적 거동)

  • Lee, Sang-Sup;Park, Keum-Sung
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.10
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    • pp.155-162
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    • 2019
  • Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

Compositional Characterization Analysis of Wall Soils Excavated in Poongnatoseong Earthen Castle, Seoul (풍납토성 성벽 토양의 성분 특성 연구)

  • Seo, Min Seok;Lee, Han Hyeong;Hu, Jun Soo;Kim, Soo Keung;Yoo, Young Mi;Lee, Seong Jun
    • Korean Journal of Heritage: History & Science
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    • v.45 no.4
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    • pp.114-125
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    • 2012
  • The purpose of this study is to analysis chromaticity, granulometry, main chemical composition and mineral crystal structure of wall soils excavated from Poongnatoseong Earthen Castle using color reader, XRD, particla size analyzer. The analysed soils of Poongnatoseong Earthen Castle were yellowish brown and isabella. All samples were sands or sands including silty soil(SW~SC) and showed similar granulometry, chemical composition and mineral crystal structure, which were characteristics of construction materials suitable for modern road or airstrip. As resulting in comparison with 4 factors from chromaticity, granulometry, main chemical composition and mineral crystal structure, we decided that the control soils(PNS) near by Poongnatoseong Earthen Castle were not to be used for the castle wall construction We presumed that there was a huge soil distribution area for the wall construction around Poongnatoseong Earthen Castle. For further study, we will make a comparison analysis all kinds of soil characteristics. And then we can understand correctly about wall soils producing area, construction method, repair method and time of Poongnatoseong Earthen Castle.

A Study on the Analytical Model of Shear Wall Considering the Current Status of Structural Design (구조설계실무 현황을 고려한 전단벽 해석모형에 관한 고찰)

  • Jung, Sung-Jin
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.9
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    • pp.3-10
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    • 2018
  • While computer environments have been dramatically developed in recent years, as the building structures become larger, the structural analysis models are also becoming more complex. So there is still a need to model one shear wall with one finite element. From the viewpoint of the concept of FEA, if one shear wall is modeled by one finite element, the result of analysis is not likely accurate. Shear wall may be modelled with various finite elements. Among them, considering the displacement compatibility condition with the beam element connected to the shear wall, plane stress element with in-plane rotational stiffness is preferred. Therefore, in order to analyze one shear wall with one finite element accurately, it is necessary to evaluate finite elements developed for the shear wall analysis and to develop various plane stress elements with rotational stiffness continuously. According to the above mentioned need, in this study, the theory about a plane stress element using hierarchical interpolation equation is reviewed and stiffness matrix is derived. And then, a computer program using this theory is developed. Developed computer program is used for numerical experiments to evaluate the analysis results using commercial programs such as SAP2000, ETABS, PERFORM-3D and MIDAS. Finally, the deflection equation of a cantilever beam with narrow rectangular section and bent by an end load P is derived according to the elasticity theory, and it is used to for comparison with theoretical solution.